North Korean leader Kim Jong Un enjoys his Dec. 1 visit to an artillery unit at an undisclosed location. Korean News Service via European Pressphoto Agency

A state photo from December 5 shows North Korean leader Kim Jong-un observing the North Korean military's winter training at an unknown location in North Korea. Korean News Service via, epa

Soldiers and citizens rally at Kim Il Sung Square in Pyongyang, North Korea, to protest a United Nations resolution condemning their country's human rights record Tuesday, Nov. 25, 2014. Protesters at the rally Tuesday on the square carried banners praising their leaders and condemning the United States. The banner in the center reads: "Let's defend with our lives the Central Committee of the Workers' Party of Korea headed by supreme leader Kim Jong Un." Jon Chol Jin, AP

North Koreans gather in front of a portrait of their late leader Kim Il Sung, left, and Kim Jong Il, right, paying respects to their late leader Kim Jong Il, to mark the third anniversary of his death, Wednesday Dec. 17 at Pyong Chon District in Pyongyang, North Korea. North Korea marked the end of a three-year mourning period for the late leader Kim Jong Il on Wednesday, opening the way for his son, Kim Jong Un, to put a more personal stamp on the way the country is run. Kim Kwang Hyon, AP

This picture taken by North Korea's official Korean Central News Agency on December 17 shows North Korean people offering prayers before portraits of late leaders Kim Il-Sung and Kim Jong-Il in Pyongyang for the third anniversary of late leader Kim Jong-Il. Korean News Service via, AFP/Getty Images

Kim Jong-Un applauds the participants in the second meeting of Korean People's Army (KPA) exemplary servicemen's families in Pyongyang in this handout image. Korean News Service via, AFP/Getty Images

This handout picture released from North Korea's official Korean Central News Agency on December 9, 2014 shows North Korean leader Kim Jong-Un holding up a boy as he joins a photo session with the participants in the second meeting of Korean People's Army exemplary servicemen's families in Pyongyang. Korean News Service via, AFP/Getty Images

An undated picture from North Korea's official Korean Central News Agency on December 5, 2014 shows North Korean leader Kim Jong-Un inspecting the new year combat and political drill of the Korean People's Army Korean News Service via, AFP/Getty Images

People enjoy a ride at the Kaeson Youth Amusement Park on Sept. 3 in Pyongyang. Wong Maye-E, AP

People shoot targets at an arcade at the Kaeson Youth Amusement Park. Wong Maye-E, AP

North Koreans enjoy an amusement park ride. Wong Maye-E, AP

Women wait for customers at a makeshift photo service stand. Wong Maye-E, AP

North Koreans scream on the free-fall ride. Wong Maye-E, AP

A portrait of North Korean leader Kim Jung Un posing with judo gold medalist An Kum Ae decorates the wall at a local gymnasium on Sept. 2 in Pyongyang. Wong Maye-E, AP

North Korean athletes practice on a trampoline. Wong Maye-E, AP

A North Korean subway station staff member waits for the arrival of a train on Sept. 1 in Pyongyang. Wong Maye-E, AP

A boy arm wrestles with former NFL player Bob "The Beast" Sapp during a wrestling goodwill tour on Aug. 29 in Pyongyang. Wong Maye-E, AP

People place flower bouquets before the statues of late North Korean leaders Kim Il-Sung and Kim Jong-Il on Mansu Hill. Korean Central News Agency via AFP/Getty Images

Women sweep around the statues of the late North Korean leaders Kim Il Sun, left, and Jong Il on the eve of the second anniversary of the death of Kim Jong Il on Dec. 16 in Pyongyang. David Guttenfelder, AP

North Koreans lay flowers at the base of statues of the late leaders Kim Il Sung and Kim Jong Il at Mansu Hill in Pyongyang. David Guttenfelder, AP

Jang Song-thaek is escorted in court on Dec. 12. The uncle of leader Kim Jong Un was executed after a shocking purge, with the state branding the once-powerful man a "traitor." Yonhap via AFP/Getty Images

A man watches a television news program showing the uncle of North Korean leader Kim Jong Un, Jang Son Thaek, at his trial at a railway station in Seoul. Ahn Young-joon, AP

Military vehicles parade during a ceremony marking the 60th anniversary of the Korean War armistice on July 27 in Pyongyang, North Korea. AP

A North Korean soldier salutes from a tank during a military parade at Kim Il-Sung Square. Ed Jones, AFP/Getty Images

Veterans of the Korean War wave to their leader, Kim Jong Un, during a military parade. David Guttenfelder, AP

People wave flags as walk with statues of former leaders Kim Il-Sung and Kim Jong-Il. Ed Jones, AFP/Getty Images

North Korean air force troops march in the parade. Ed Jones, AFP/Getty Images

A North Korean soldier salutes from his tank. Wong Maye-E, AP

Soldiers march through Kim Il Sung Square. Wong Maye-E, AP

A unit of women soldiers march in formation. Ed Jones, AFP/Getty Images

People wave flowers during the parade. Ed Jones, AFP/Getty Images

People carry a portrait of former leader Kim Jong-Il. Ed Jones, AFP/Getty Images

Dancers parade through Kim Il Sung Sqaure. Wong Maye-E, AP

Thousands of people hold up colored squares as they create a giant North Korean flag as they celebrate the 60th anniversary of the Korean War armistice during a performance at the Rungnado May Day Stadium on July 26 in Pyongyang. Ed Jones, AFP/Getty Images

People hold colored material as they watch for their cue during a performance. One hundred thousand people created a synchronized socialist-realist performance in a 90 minute display of gymnastics, dance and acrobatics. Ed Jones, AFP/Getty Images

Dancers perform in Pyongyang. Ed Jones, AFP/Getty Images

Performers present a program on the field of the Rungnado May Day Stadium. Ed Jones, AFP/Getty Images

North Korean soldiers walk along a road in front of the truce village of Panmunjom at the Demilitarized Zone on July 22. David Guttenfelder, AP

North Korean pedestrians and bicyclists pass by a billboard for Pyeonghwa Motors, North Korea's car manufacturer, on a highway on the outskirts of Pyongyang. David Guttenfelder, AP

North Koreans stand to applaud during the opening night of the "Arirang" mass games performance at Pyongyang's May Day Stadium on July 22. This year's performance was timed to debut for the 60th anniversary of the end of the Korean War. David Guttenfelder, AP

At dusk, the setting sunlight is reflected on the Taedong River in Pyongyang, North Korea, on July 21. David Guttenfelder, AP

North Koreans clean a street after a heavy rainfall in Kaesong, North Korea. David Guttenfelder, AP

Thousands of North Koreans turn colored cards to create an image of the Unha-3 rocket that North Korea successfully launched in December 2012 during the Arirang mass games. David Guttenfelder, AP

A North Korean soldier sits inside a room in Panmunjom inside the Demilitarized Zone (DMZ). David Guttenfelder, AP

North Koreans ride bicycles in the rain along the Taedong River bank in Pyongyang, North Korea. David Guttenfelder, AP

North Korean soldiers walk on a highway near the North Korean city of Kaesong. David Guttenfelder, AP

North Korean nurses sing and play the accordion while children dance during an event to start a campaign to give vitamin A supplements and deworming pills to children at a nursery school in Pyongyang, North Korea, on Child Health Day, May 20. UNICEF and North Korean government agencies are collaborating in the campaign to assist 1.7 million children across the country under age 5. David Guttenfelder, AP

North Korean nurses give vitamin A supplements and deworming pills to children dressed in their best outfits at an elite nursery school in Pyongyang, North Korea. David Guttenfelder, AP

North Koreans pass by the outer wall of a construction site where a propaganda billboard depicts the launch of North Korean rockets in Pyongyang, North Korea. The billboard reads: "Let's open up an era to a strong economic country." David Guttenfelder, AP

North Koreans play a board game inside a sauna at the Haedanghwa Health Complex in Pyongyang, North Korea, on May 19. The newly opened complex houses a cooking school, multiple banquet rooms, swimming and wading pools, a billiards room and other spa and recreational facilities. David Guttenfelder, AP

North Korean swimmers enter a waterfall wading pool inside the Haedanghwa Health Complex in Pyongyang, North Korea. David Guttenfelder, AP

Wearing gym-provided workout clothing, North Koreans rest near the gym at the Haedanghwa Health Complex in Pyongyang, North Korea. David Guttenfelder, AP

Portraits of former North Korean leaders Kim Il Sung, left, and Kim Jong Il hang on the outside of a building in central Pyongyang, North Korea, on May 18. David Guttenfelder, AP

North Korean soldiers and civilians pose for photos April 25 as they tour the grounds of Kumsusan Palace of the Sun, the mausoleum in Pyongyang where the bodies of former leaders Kim Il Sung and Kim Jong Il lie embalmed. Last month, North Korea marked the 81st anniversary of the founding of its military, which began as an anti-Japanese militia and now has an estimated 1.2 million troops. David Guttenfelder, AP

North Korean soldiers tour the park surrounding Kumsusan Palace of the Sun. David Guttenfelder, AP

North Korean army Col. Kim Chang Jun stands behind field binoculars on a hilltop overlooking the Demilitarized Zone, south of Kaesong, North Korea, on April 24. David Guttenfelder, AP

A boy walks along a path in front of a village south of Kaesong, North Korea. David Guttenfelder, AP

A North Korean boy rides in a bicycle basket on a road north of Kaesong, North Korea. David Guttenfelder, AP

A North Korean boy on rollerblades is pulled by a woman on a bicycle on a road south of Kaesong, North Korea and north of the demilitarized zone which separates the two Koreas. David Guttenfelder, AP

A North Korean man checks his bicycle next to a propaganda billboard in Kaesong, North Korea. David Guttenfelder, AP

North Korean soldiers ride in the top of a military truck on a road in Kaesong, North Korea. For weeks, North Korea has threatened to attack the U.S. and South Korea for holding joint military drills and for supporting U.N. sanctions. Washington and Seoul officials said they've seen no evidence that Pyongyang is actually preparing for a major conflict, though South Korean defense officials said the North appears prepared to test-fire a medium-range missile. David Guttenfelder, AP

North Korean farmers work in a field inside the Demilitarized Zone at Panmunjom, North Korea. David Guttenfelder, AP

A North Korean traffic policeman stands at an intersection in Kaesong, North Korea on April 23. David Guttenfelder, AP

North Koreans walk bicycles along a street in Kaesong, North Korea. David Guttenfelder, AP

North Korean children walk in front of an apartment block in Kaesong, North Korea. David Guttenfelder, AP

North Korean soldiers stand on steps overlooking the border village of Panmunjom, North Korea. David Guttenfelder, AP

A painting, depicting North Korean soldiers ambushing and killing U.S. troops hangs on a gallery wall at an art exhibition Friday in Pyongyang. David Guttenfelder, AP

A North Korean boy practices his lines -- "Our country is the greatest in the world" -- as he is filmed by a local television crew at an exhibition of traditional calligraphy in Pyongyang. David Guttenfelder, AP

North Korean children perform in front of an image of weapons and bayonetsat Mangyongdae Children's Palace in Pyongyang. David Guttenfelder, AP

Children practice a musical performance at Mangyongdae Children's Palace. David Guttenfelder, AP

A guide stands in a waiting room at Mangyongdae Children's Palace in Pyongyang. Portraits in the background show North Korea's late leaders Kim Il Sung, left, and Kim Jong Il. David Guttenfelder, AP

Children work at easels during a drawing class at Mangyongdae Children's Palace. David Guttenfelder, AP

A North Korean soldier plows a field on the outskirts of Pyongyang. David Guttenfelder, AP

North Koreans walk along a sidewalk in Pyongyang. David Guttenfelder, AP

A North Korean soldier walks through a parking lot as workers paint a building block across the street in Pyongyang. David Guttenfelder, AP

A North Korean soldier guarding the entrance to Pyongyang's Kumsusan mausoleum, where the bodies of the late leaders Kim Il Sung and Kim Jong Il lie embalmed, looks back through the doors of the main gate Monday, April 15, 2013. North Koreans turned out on Monday to mark the 101st birthday of Kim Il Sung. David Guttenfelder, AP

A North Korean man misses the turn and loses control of his go cart on a track at the Fun Fair in Pyongyang on Tuesday, April 16, 2013. David Guttenfelder, AP

A North Korean child covers the eyes of her father as she sits on his shoulders watching mass folk dancing in front of Pyongyang Indoor Stadium in Pyongyang, North Korea. Oblivious to international tensions over a possible North Korean missile launch, Pyongyang residents spilled into the streets Monday to celebrate a major national holiday, the birthday of their first leader, Kim Il Sung. David Guttenfelder, AP

North Korean commuters ride on a city trolley bus in Pyongyang. David Guttenfelder, AP

Marathon runners pass by a long row of North Korean soldiers as they cross a bridge in Pyongyang on Sunday, April 14, 2013. North Korea hosted the 26th Mangyongdae Prize Marathon to mark the April 15, 2013 birthday of the late leader Kim Il Sung. David Guttenfelder, AP

A North Korean woman walks past the outer wall of a construction site where a propaganda billboard depicting the launch of North Korean rockets in Pyongyang, North Korea. The billboard reads: "Lets open up an era to a strong economic country." David Guttenfelder, AP

North Korean children hold up red scarves to be tied around their necks during an induction ceremony into the Korean Children's Union, the first political organization for North Koreans, held at a stadium in Pyongyang on Friday, April 12, 2013. David Guttenfelder, AP

North Koreans dance together beneath a mosaic painting of the late leader Kim Il Sung during a mass folk dancing gathering in Pyongyang Thursday, April 11, 2013, to mark the anniversary of the first of many titles of power given to leader Kim Jong Un after the death of his father Kim Jong Il. David Guttenfelder, AP

A North Korean man pushes a bicycle up a hill on the outskirts of Pyongyang. David Guttenfelder, AP